1 #ifndef _FAT_H 2 #define _FAT_H 3 4 #include <linux/buffer_head.h> 5 #include <linux/string.h> 6 #include <linux/nls.h> 7 #include <linux/fs.h> 8 #include <linux/hash.h> 9 #include <linux/mutex.h> 10 #include <linux/ratelimit.h> 11 #include <linux/msdos_fs.h> 12 13 /* 14 * vfat shortname flags 15 */ 16 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */ 17 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */ 18 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */ 19 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */ 20 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */ 21 22 #define FAT_ERRORS_CONT 1 /* ignore error and continue */ 23 #define FAT_ERRORS_PANIC 2 /* panic on error */ 24 #define FAT_ERRORS_RO 3 /* remount r/o on error */ 25 26 #define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */ 27 #define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */ 28 29 struct fat_mount_options { 30 kuid_t fs_uid; 31 kgid_t fs_gid; 32 unsigned short fs_fmask; 33 unsigned short fs_dmask; 34 unsigned short codepage; /* Codepage for shortname conversions */ 35 int time_offset; /* Offset of timestamps from UTC (in minutes) */ 36 char *iocharset; /* Charset used for filename input/display */ 37 unsigned short shortname; /* flags for shortname display/create rule */ 38 unsigned char name_check; /* r = relaxed, n = normal, s = strict */ 39 unsigned char errors; /* On error: continue, panic, remount-ro */ 40 unsigned char nfs; /* NFS support: nostale_ro, stale_rw */ 41 unsigned short allow_utime;/* permission for setting the [am]time */ 42 unsigned quiet:1, /* set = fake successful chmods and chowns */ 43 showexec:1, /* set = only set x bit for com/exe/bat */ 44 sys_immutable:1, /* set = system files are immutable */ 45 dotsOK:1, /* set = hidden and system files are named '.filename' */ 46 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ 47 utf8:1, /* Use of UTF-8 character set (Default) */ 48 unicode_xlate:1, /* create escape sequences for unhandled Unicode */ 49 numtail:1, /* Does first alias have a numeric '~1' type tail? */ 50 flush:1, /* write things quickly */ 51 nocase:1, /* Does this need case conversion? 0=need case conversion*/ 52 usefree:1, /* Use free_clusters for FAT32 */ 53 tz_set:1, /* Filesystem timestamps' offset set */ 54 rodir:1, /* allow ATTR_RO for directory */ 55 discard:1; /* Issue discard requests on deletions */ 56 }; 57 58 #define FAT_HASH_BITS 8 59 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 60 61 /* 62 * MS-DOS file system in-core superblock data 63 */ 64 struct msdos_sb_info { 65 unsigned short sec_per_clus; /* sectors/cluster */ 66 unsigned short cluster_bits; /* log2(cluster_size) */ 67 unsigned int cluster_size; /* cluster size */ 68 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */ 69 unsigned short fat_start; 70 unsigned long fat_length; /* FAT start & length (sec.) */ 71 unsigned long dir_start; 72 unsigned short dir_entries; /* root dir start & entries */ 73 unsigned long data_start; /* first data sector */ 74 unsigned long max_cluster; /* maximum cluster number */ 75 unsigned long root_cluster; /* first cluster of the root directory */ 76 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 77 struct mutex fat_lock; 78 struct mutex s_lock; 79 unsigned int prev_free; /* previously allocated cluster number */ 80 unsigned int free_clusters; /* -1 if undefined */ 81 unsigned int free_clus_valid; /* is free_clusters valid? */ 82 struct fat_mount_options options; 83 struct nls_table *nls_disk; /* Codepage used on disk */ 84 struct nls_table *nls_io; /* Charset used for input and display */ 85 const void *dir_ops; /* Opaque; default directory operations */ 86 int dir_per_block; /* dir entries per block */ 87 int dir_per_block_bits; /* log2(dir_per_block) */ 88 89 int fatent_shift; 90 struct fatent_operations *fatent_ops; 91 struct inode *fat_inode; 92 struct inode *fsinfo_inode; 93 94 struct ratelimit_state ratelimit; 95 96 spinlock_t inode_hash_lock; 97 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 98 99 spinlock_t dir_hash_lock; 100 struct hlist_head dir_hashtable[FAT_HASH_SIZE]; 101 102 unsigned int dirty; /* fs state before mount */ 103 }; 104 105 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 106 107 /* 108 * MS-DOS file system inode data in memory 109 */ 110 struct msdos_inode_info { 111 spinlock_t cache_lru_lock; 112 struct list_head cache_lru; 113 int nr_caches; 114 /* for avoiding the race between fat_free() and fat_get_cluster() */ 115 unsigned int cache_valid_id; 116 117 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ 118 loff_t mmu_private; /* physically allocated size */ 119 120 int i_start; /* first cluster or 0 */ 121 int i_logstart; /* logical first cluster */ 122 int i_attrs; /* unused attribute bits */ 123 loff_t i_pos; /* on-disk position of directory entry or 0 */ 124 struct hlist_node i_fat_hash; /* hash by i_location */ 125 struct hlist_node i_dir_hash; /* hash by i_logstart */ 126 struct rw_semaphore truncate_lock; /* protect bmap against truncate */ 127 struct inode vfs_inode; 128 }; 129 130 struct fat_slot_info { 131 loff_t i_pos; /* on-disk position of directory entry */ 132 loff_t slot_off; /* offset for slot or de start */ 133 int nr_slots; /* number of slots + 1(de) in filename */ 134 struct msdos_dir_entry *de; 135 struct buffer_head *bh; 136 }; 137 138 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 139 { 140 return sb->s_fs_info; 141 } 142 143 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 144 { 145 return container_of(inode, struct msdos_inode_info, vfs_inode); 146 } 147 148 /* 149 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to 150 * save ATTR_RO instead of ->i_mode. 151 * 152 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only 153 * bit, it's just used as flag for app. 154 */ 155 static inline int fat_mode_can_hold_ro(struct inode *inode) 156 { 157 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 158 umode_t mask; 159 160 if (S_ISDIR(inode->i_mode)) { 161 if (!sbi->options.rodir) 162 return 0; 163 mask = ~sbi->options.fs_dmask; 164 } else 165 mask = ~sbi->options.fs_fmask; 166 167 if (!(mask & S_IWUGO)) 168 return 0; 169 return 1; 170 } 171 172 /* Convert attribute bits and a mask to the UNIX mode. */ 173 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, 174 u8 attrs, umode_t mode) 175 { 176 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) 177 mode &= ~S_IWUGO; 178 179 if (attrs & ATTR_DIR) 180 return (mode & ~sbi->options.fs_dmask) | S_IFDIR; 181 else 182 return (mode & ~sbi->options.fs_fmask) | S_IFREG; 183 } 184 185 /* Return the FAT attribute byte for this inode */ 186 static inline u8 fat_make_attrs(struct inode *inode) 187 { 188 u8 attrs = MSDOS_I(inode)->i_attrs; 189 if (S_ISDIR(inode->i_mode)) 190 attrs |= ATTR_DIR; 191 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) 192 attrs |= ATTR_RO; 193 return attrs; 194 } 195 196 static inline void fat_save_attrs(struct inode *inode, u8 attrs) 197 { 198 if (fat_mode_can_hold_ro(inode)) 199 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; 200 else 201 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); 202 } 203 204 static inline unsigned char fat_checksum(const __u8 *name) 205 { 206 unsigned char s = name[0]; 207 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 208 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 209 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 210 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 211 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 212 return s; 213 } 214 215 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 216 { 217 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 218 + sbi->data_start; 219 } 220 221 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 222 { 223 #ifdef __BIG_ENDIAN 224 while (len--) { 225 *dst++ = src[0] | (src[1] << 8); 226 src += 2; 227 } 228 #else 229 memcpy(dst, src, len * 2); 230 #endif 231 } 232 233 static inline int fat_get_start(const struct msdos_sb_info *sbi, 234 const struct msdos_dir_entry *de) 235 { 236 int cluster = le16_to_cpu(de->start); 237 if (sbi->fat_bits == 32) 238 cluster |= (le16_to_cpu(de->starthi) << 16); 239 return cluster; 240 } 241 242 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) 243 { 244 de->start = cpu_to_le16(cluster); 245 de->starthi = cpu_to_le16(cluster >> 16); 246 } 247 248 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 249 { 250 #ifdef __BIG_ENDIAN 251 while (len--) { 252 dst[0] = *src & 0x00FF; 253 dst[1] = (*src & 0xFF00) >> 8; 254 dst += 2; 255 src++; 256 } 257 #else 258 memcpy(dst, src, len * 2); 259 #endif 260 } 261 262 /* fat/cache.c */ 263 extern void fat_cache_inval_inode(struct inode *inode); 264 extern int fat_get_cluster(struct inode *inode, int cluster, 265 int *fclus, int *dclus); 266 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 267 unsigned long *mapped_blocks, int create); 268 269 /* fat/dir.c */ 270 extern const struct file_operations fat_dir_operations; 271 extern int fat_search_long(struct inode *inode, const unsigned char *name, 272 int name_len, struct fat_slot_info *sinfo); 273 extern int fat_dir_empty(struct inode *dir); 274 extern int fat_subdirs(struct inode *dir); 275 extern int fat_scan(struct inode *dir, const unsigned char *name, 276 struct fat_slot_info *sinfo); 277 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 278 struct msdos_dir_entry **de); 279 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 280 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 281 struct fat_slot_info *sinfo); 282 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 283 284 /* fat/fatent.c */ 285 struct fat_entry { 286 int entry; 287 union { 288 u8 *ent12_p[2]; 289 __le16 *ent16_p; 290 __le32 *ent32_p; 291 } u; 292 int nr_bhs; 293 struct buffer_head *bhs[2]; 294 struct inode *fat_inode; 295 }; 296 297 static inline void fatent_init(struct fat_entry *fatent) 298 { 299 fatent->nr_bhs = 0; 300 fatent->entry = 0; 301 fatent->u.ent32_p = NULL; 302 fatent->bhs[0] = fatent->bhs[1] = NULL; 303 fatent->fat_inode = NULL; 304 } 305 306 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 307 { 308 fatent->entry = entry; 309 fatent->u.ent32_p = NULL; 310 } 311 312 static inline void fatent_brelse(struct fat_entry *fatent) 313 { 314 int i; 315 fatent->u.ent32_p = NULL; 316 for (i = 0; i < fatent->nr_bhs; i++) 317 brelse(fatent->bhs[i]); 318 fatent->nr_bhs = 0; 319 fatent->bhs[0] = fatent->bhs[1] = NULL; 320 fatent->fat_inode = NULL; 321 } 322 323 extern void fat_ent_access_init(struct super_block *sb); 324 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 325 int entry); 326 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 327 int new, int wait); 328 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 329 int nr_cluster); 330 extern int fat_free_clusters(struct inode *inode, int cluster); 331 extern int fat_count_free_clusters(struct super_block *sb); 332 333 /* fat/file.c */ 334 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 335 unsigned long arg); 336 extern const struct file_operations fat_file_operations; 337 extern const struct inode_operations fat_file_inode_operations; 338 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 339 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 340 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 341 struct kstat *stat); 342 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 343 int datasync); 344 345 /* fat/inode.c */ 346 extern void fat_attach(struct inode *inode, loff_t i_pos); 347 extern void fat_detach(struct inode *inode); 348 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 349 extern struct inode *fat_build_inode(struct super_block *sb, 350 struct msdos_dir_entry *de, loff_t i_pos); 351 extern int fat_sync_inode(struct inode *inode); 352 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 353 int isvfat, void (*setup)(struct super_block *)); 354 355 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 356 struct inode *i2); 357 static inline unsigned long fat_dir_hash(int logstart) 358 { 359 return hash_32(logstart, FAT_HASH_BITS); 360 } 361 362 /* fat/misc.c */ 363 extern __printf(3, 4) __cold 364 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 365 #define fat_fs_error(sb, fmt, args...) \ 366 __fat_fs_error(sb, 1, fmt , ## args) 367 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 368 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 369 __printf(3, 4) __cold 370 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 371 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 372 do { \ 373 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 374 fat_msg(sb, level, fmt, ## args); \ 375 } while (0) 376 extern int fat_clusters_flush(struct super_block *sb); 377 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 378 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 379 __le16 __time, __le16 __date, u8 time_cs); 380 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 381 __le16 *time, __le16 *date, u8 *time_cs); 382 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 383 384 int fat_cache_init(void); 385 void fat_cache_destroy(void); 386 387 /* fat/nfs.c */ 388 struct fid; 389 extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, 390 int fh_len, int fh_type); 391 extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, 392 int fh_len, int fh_type); 393 extern struct dentry *fat_get_parent(struct dentry *child_dir); 394 395 /* helper for printk */ 396 typedef unsigned long long llu; 397 398 #endif /* !_FAT_H */ 399